Pile



J. J. O BRIEN Dec. 4, 1934.

PILE

Filed May 29, 1931 INVENTOR. 32M). 0

ATTORNEYS.

Fig.4-

Patented Dec. 4, 1934 UNITED STA TES PATENr OFFIE 4 Claims.

The main object of the invention is to provide a supporting foundationstructure, or pile, Whose bearing strength and frictional resistivestrength.

may be materially increased after the structure 5 has penetrated toa-predetermined or maximum depth. This object is accomplished byproviding means, such as projections or prongs, operable from the headof the pile, which effect a lateral or radial penetration of the soilsurrounding the main pile body. The prongs are preferably so arrangedand operated that they offerlittle or no resistance to the driving ofthe pile and do not ordinarily function as specified until after the,pile is driven. However, they are operable, at the will of the operator,at any stage of the pile driving operation. The prongs may be of anynumber, size or shape, and may be arranged. at'idifferent levels alongthe pile and may extend," when in ultimate functioning position, indifferent ra-' .20 dial directions from the axis of the pile; so thatthe controlling factor in the amount of load that can be carried by thepile approaches the strength of the materials of which the pile isconstructed. Approximately full strength of the pile may .25 be obtainedwith a materially decreased driving force due to the small percentage oftotal area of the pile exposed to soil resistance against driving todesired possible penetration, which has the effect of exerting therequired force per square inch to overcome soil resistance to driving,with.

a materially decreased total driving force.

A total strength of pile equal to that of any other pile heretofore usedmay be obtained with much less penetration.

. By spreading the bearing area and frictional resistance area by themeans specified, the arch action of soil resistance may be utilized andadvantage may be taken of the possibly strong resistive strata throughwhich the pile may extend,

. any voids that may exist being closed by grouting or pressure groutingwith cement mortar or cement concrete.

In the drawing, which shows one embodiment of the invention, and amodification thereof: Fig. 1 is a vertical section through the middle ofthe pile before the inner mandrel is driven home relative to the shell.

Fig. 2 is a plan view of the top of the pile. Fig. 3 is a horizontalsection on the line 3-3 .50 of Fig. 1.

Fig. 6 is a vertical section of an attachment that may replacetheattachment shown in Figs. 1 and 3 and that isespecially adaptable forhard driving.

Fig. '7 is a bottom view of the attachment of Fig. 6.

The pile comprises an outer casing or shell 1 and an inner mandrel 2.During the driving of the pile and until just before the mandrel isdriven home, the mandrel and casing may be held in fixedrelation one tothe other by means of the attachment shown in Figs. 1 and 3. Theattachmentcomprises'two angle plates 6, 6, two flat plates, '7, 7,twobolts and nuts 10, 10, two bolts and nuts 13, 13, and a washer 14.The mandrel 2 projects above this attachment and carries a cap 8, onwhich the driving is done. Until'the casingis driven, by action upon thecap of the mandrel, to its desired maximum penetration; the casing andmandrel maintain the relative position shown in Fig. 1. The casing has aclosed bottom 9.

Hinged to the mandrel 2 at various points along its length and ondifierent radii of its axis (say on four radii 90 apart) are prongs 3.The prongs maybe hinged by bolts and nuts 11 and pipe separators 12. Thefree ends of the prongs rest on guide flaps 5 inclined downward towardorifices in the Wall of the casing.

During the driving of the pile and until the casing has penerated to thedesired-depth, the prongs 3 are functionless and since they do notextend out beyond the casing wall, they offer no resistance to driving.When the casing has penetrated to the desired depth, the above describedattach- 90 ment securing the casing 1 to the mandrel 2 is removed andthe mandrel 2 is driven down within the shell. During this operation theprongs 3, guided by the flaps 5, swing on their pivots and at the sametime are forced out through the orifices 95 in the casing and throughthe surrounding soil until, when the mandrel is driven home, they occupythe radial positions shown in Figs. 4 and 5. In this position the prongsare supported, at their hinged ends, by the braces 4, and the flaps 5have been bent down into the horizontal position shown inFig. 4, theflaps in this position affording an additional support for the prongs.

The pile is grouted with cement mortar or cement concrete by filling thepile with grout either just before or just after driving the mandrelhome. The grout may be injected by any known process, as, for example,by the method known as pressure grouting, wherein an attachment at theend of the pile forces the grout into all cavities by the pressure ofcompressed air. A combination of known methods of grouting may beemployed. The length and size of the pile will determine whether cementmortar or cement concrete shall be used and also by what method to applythe grout. When the grout filler has set suificiently, the pile is readyfor its load.

Instead of using the attachment above described, and shown in Figs. land 3, for securing together the mandrel and casing, the attachmentshown in Figs. 6 and 7 may be used. In this attachment a key 16 rests onthe top of the casing 1 and under the mandrel braces 4, 4. A sleeve 15,

carrying the cap 8, is then placed over the top of the mandrel, 2,resting on the top of the casing 1, the key fitting into diametricallyopposite notches in the sleeve. When this attachment is used,'thedriving force is transmitted direct to the outer casing. When the pilehas reached its desired maximum or possible penetration the attachmentis removed and the inner mandrel is driven home as hereinbeforedescribed.

The pile is protected,when necessary, by a. rust-resisting process, suchas galvanizing or painting.

The above embodiments of the invention are merely illustrative. Ifeither of the embodiments described be used, the details may be varied.

. Thus, for the bolts by which the prongs are hung tion. The invention,however, may assume forms specifically quite difierent from thosedescribed, to which I do not wish to be limited.

Having now fully described my invention, what I claim and desire toprotect by Letters Patent is:

1. A pile comprising an outer casing, an inner mandrel, and prongscarried by the mandrel at different levels within the casing andoperable, by a downward movement of the mandrel relative 7 to thecasing, to be projected laterally through the wall of the casing.

"2. A pile comprising an outer casing having orifices at differentlevels, an inner mandrel, prongs hinged on the mandrel adjacent saidopenings; and guides on the casing adapted, when the mandrel is moveddownward relative to the casing, to'constrain the prongs pivoted to themandrel and to swing on their axes through said orifices toward ahorizontal position.

3. A pile comprising an outer casing, an inner mandrel, soil-penetratingdevices pivoted on said mandrel, means for holding said casing andmandrel against relative vertical movement, and means for guiding thesoil-penetrating devices outwardly through the wall of the casing uponrelative movement of the mandrel and easing following release of theholding means.

4. A pile comprising an outer casing, an inner mandrel, soil-penetratingdevices pivoted on said mandrel, means for holding said casing andmandrel against relative vertical movement, said holding means forming aconnection between the mandrel and casing whereby driving blows to sinkthe casing may be applied to the mandrel,

and'means for guiding the soil-penetrating devices outwardly through thewall of the casing upon relative movement of the mandrel and casingfollowing release of the holding means.

JAMES J. OBRIEN.

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